background color for active links in css rgba code example

Example: css how to style a

/*a normal, unvisited link*/
a:link{
	color: green;
}
/*a link the user has visited*/
a:visited{
	color: purple;
}
/*a link when the user mouses over it*/
a:hover{
	color: yellow;
}
/*a link the moment it is clicked*/
a:active{
	color: brown;
}